Phase-driven progress in nanophotonic biosensing

Abstract In the continuous pursuit of enhancing the sensitivity of nanophotonic biosensors by leveraging phase phenomena, a recent development involved the engineering of an atomically thin Ge 2 Sb 2 Te 5 layer on a silver nanofilm to generate large Goos–Hänchen-shifts associated with phase singularities. The resulting detection limit reached ~7 × 10 −7 RIU.